Ok it runs great on start up, after a couple minutes it hesitates on light throttle and slowly fouls the plug. I've cleaned the carb about 20 times, replaced the ignition coil, brand new gas tank, done all the basic stuff. Assuming it's not a dirty carb what else could it be. I'm running out of options.
What year is the bike?
What all have you done to the carburetor?
Do you have a WOT miss? Back off just a little and it is OK?
Long live the internal combustion engine!
Bike is an 06. The miss is on takeoff it screams at wot and the carb has been dipped cleaned thoroughly and main jet replaced. Cdi was my next thought
I went through that too.I changed all the cheap stuff first then the CDI and now it's like new.